diff options
Diffstat (limited to 'target-arm/translate-a64.c')
| -rw-r--r-- | target-arm/translate-a64.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index 5c13e153d4..529bb0c41d 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -30,6 +30,7 @@ #include "internals.h" #include "qemu/host-utils.h" +#include "exec/semihost.h" #include "exec/gen-icount.h" #include "exec/helper-proto.h" @@ -1553,8 +1554,27 @@ static void disas_exc(DisasContext *s, uint32_t insn) unallocated_encoding(s); break; } - /* HLT */ - unsupported_encoding(s, insn); + /* HLT. This has two purposes. + * Architecturally, it is an external halting debug instruction. + * Since QEMU doesn't implement external debug, we treat this as + * it is required for halting debug disabled: it will UNDEF. + * Secondly, "HLT 0xf000" is the A64 semihosting syscall instruction. + */ + if (semihosting_enabled() && imm16 == 0xf000) { +#ifndef CONFIG_USER_ONLY + /* In system mode, don't allow userspace access to semihosting, + * to provide some semblance of security (and for consistency + * with our 32-bit semihosting). + */ + if (s->current_el == 0) { + unsupported_encoding(s, insn); + break; + } +#endif + gen_exception_internal_insn(s, 0, EXCP_SEMIHOST); + } else { + unsupported_encoding(s, insn); + } break; case 5: if (op2_ll < 1 || op2_ll > 3) { |